This invention relates generally to an apparatus for extracting a film unit from a film magazine or pack. More particularly, it relates to an apparatus for extracting successive bottommost film units from an array of self-developing film units stacked in the film pack.
With the advent of instant photography, photographic apparatus of the self-developing type have been devised in which the exposure, processing and ejecting operations of self-developing type film are carried out within the same apparatus. Such apparatus and film are disclosed in several U.S. patents assigned in common herewith. Typically, this apparatus includes a camera body housing a film pack containing a stacked array of film units. The pack itself has a film exit slot located adjacent a pair of pressure-applying rollers. These rollers are also mounted adjacent a camera body exit slot through which a film unit is advanced from the pack after being exposed.
For advancing the film unit from the pack after exposure, there is provided a film pick mechanism. A wide variety of such mechanisms exist. Typically, these include a film pick unit which is advanced to engage a marginal edge of the film unit which is opposite to the rupturable pod of such unit. Picking advances the topmost film unit of the film pack through the film pack exit slot so that the rupturable pod is brought into engagement with the rollers, whereupon it is further advanced by them through the camera body exit slot. Simultaneously and progressively the rollers cause uniform spreading of the processing fluid in the film unit. Exemplary ones of these different kinds of picking mechanisms are disclosed in commonly-assigned U.S. Pat. Nos. 3,675,551; 3,678,830; 3,653,308; 3,561,346; 3,511,152; 3,760,701; 4,126,875; 4,047,192. Picking of the type disclosed is preferable for a number of reasons. One being that it simplifies the steps and mechanisms necessary to feed the film unit to the processing rollers. While the picking described in the foregoing patents involved picking of the topmost units, there are situations in which it is desirable to pick from the bottom of the stack. U.S. Pat. Nos. 3,525,293; 4,114,166; 4,318,601 are illustrative of cameras in which this occurs.
It is to be noted that all of the noted picking mechanisms employ a so-called rear picking type mechanism, that is one in which the film units are advanced in a direction and manner such that during film advancement the marginal edge containing the pod initially engages the rollers.
It has been determined that when removing the bottommost film unit, of the standard flexible self-developing type, from a stack of such units, the potential for mis-picking and double-picking is increased. Clearly, it is highly desirable to avoid such problems.